| Message ID | 20240529162527.3688979-1-kuba@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 4fdb6b6063f07d959a1c52a2ee580afc4da34e2d |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] net: count drops due to missing qdisc as dev->tx_drops | expand |
Hello: This patch was applied to netdev/net-next.git (main) by Paolo Abeni <pabeni@redhat.com>: On Wed, 29 May 2024 09:25:27 -0700 you wrote: > Catching and debugging missing qdiscs is pretty tricky. When qdisc > is deleted we replace it with a noop qdisc, which silently drops > all the packets. Since the noop qdisc has a single static instance > we can't count drops at the qdisc level. Count them as dev->tx_drops. > > ip netns add red > ip link add type veth peer netns red > ip link set dev veth0 up > ip -netns red link set dev veth0 up > ip a a dev veth0 10.0.0.1/24 > ip -netns red a a dev veth0 10.0.0.2/24 > ping -c 2 10.0.0.2 > # 2 packets transmitted, 2 received, 0% packet loss, time 1031ms > ip -s link show dev veth0 > # TX: bytes packets errors dropped carrier collsns > # 1314 17 0 0 0 0 > > [...] Here is the summary with links: - [net-next] net: count drops due to missing qdisc as dev->tx_drops https://git.kernel.org/netdev/net-next/c/4fdb6b6063f0 You are awesome, thank you!
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 2a637a17061b..1417f1991452 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -633,6 +633,7 @@ EXPORT_SYMBOL_GPL(netif_carrier_event); static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc, struct sk_buff **to_free) { + dev_core_stats_tx_dropped_inc(skb->dev); __qdisc_drop(skb, to_free); return NET_XMIT_CN; }
Catching and debugging missing qdiscs is pretty tricky. When qdisc is deleted we replace it with a noop qdisc, which silently drops all the packets. Since the noop qdisc has a single static instance we can't count drops at the qdisc level. Count them as dev->tx_drops. ip netns add red ip link add type veth peer netns red ip link set dev veth0 up ip -netns red link set dev veth0 up ip a a dev veth0 10.0.0.1/24 ip -netns red a a dev veth0 10.0.0.2/24 ping -c 2 10.0.0.2 # 2 packets transmitted, 2 received, 0% packet loss, time 1031ms ip -s link show dev veth0 # TX: bytes packets errors dropped carrier collsns # 1314 17 0 0 0 0 tc qdisc replace dev veth0 root handle 1234: mq tc qdisc replace dev veth0 parent 1234:1 pfifo tc qdisc del dev veth0 parent 1234:1 ping -c 2 10.0.0.2 # 2 packets transmitted, 0 received, 100% packet loss, time 1034ms ip -s link show dev veth0 # TX: bytes packets errors dropped carrier collsns # 1314 17 0 3 0 0 Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- CC: jhs@mojatatu.com CC: xiyou.wangcong@gmail.com CC: jiri@resnulli.us --- net/sched/sch_generic.c | 1 + 1 file changed, 1 insertion(+)